Temporary Power Generators can be found throughout both games in Left 4 Dead and Left 4 Dead 2. They are diesel generators of a standard industrial design. They are frequently encountered throughout both games and provide the basis for survivor task-roles in the Crash Course, The Passing and The Sacrifice campaigns.

The general principle is that this equipment has been brought in by CEDA to supply electric current either to augment the power grid or to replace it when mains electricity has failed. These generators deliver power to floodlights, workshop equipment and operationally important infrastructure such as the river bridge at Rayford.

Stay together as a group and try to be relatively close to the generators themselves, especially the generators in the original Left 4 Dead, since they stall out and require the Survivors to restart them.

Ensure the Survivors are providing cover to the lone Survivor restarting the generators as the horde will continue to attack, making that Survivor more vulnerable to hits and taking damage.

Similar strategy when pouring gas into the generator in Left 4 Dead 2: Stay as a group and move together to get more gas cans, to ensure less vulnerability to the Infected.

Cover the lone Survivor who is currently pouring the gas can into the generator as, again, they are more vulnerable to hits from the horde.

There are only two generators throughout the series which are known to stall out and a Survivor is required to go back and restart it.

Even though there is a flip switch visible on the generator in the Truck Depot Finale, a Survivor has to start a crank manually instead of flipping the switch.

All of the Survivors clearly hate using the generators as they are noisy (which attracts hordes) and takes too long to respond to the needs of the Survivors:

Francis or Zoey (depends who's driving the truck) may have run over the generator at the truck depot (as they both state their hatred when they restart the generator the second time); however, the rescue vehicle is seen pulling out and driving away, avoiding the generator completely.

Nick, Ellis, Coach, and Rochelle comment on how much gas the generator needs to take before becoming fully functional and operational. Arguably, Nick clearly despises filling up generators the most compared to the other Survivors as evidenced by his quotes, especially "Why doesn't anything have enough gas in it?"

Bill may even comment that idiots tend to fill things with gas, something that the new Survivors have been burdened with.

The generators at Rayford Port are the only ones that require the original Survivors to crank manually first, then to power it up before it apparently runs out of fuel; whereas the other group of new Survivors have to find more fuel for it.